The present invention relates to a dampening apparatus, and more particularly, a compact dampening apparatus that provides consistent performance characteristics over a wide range of temperatures.
In order to draw enemy fire from an aircraft, drones have been developed that are pulled behind the aircraft by a cable connected to the aircraft. The drone attracts enemy missile fire by having the guidance system of the missile lock onto the drone as opposed to the aircraft. If such an event occurs, the drone is destroyed at a sufficiently safe distance from the aircraft so as to prevent any damage to the aircraft.
In deploying the drones, the drones are typically released from the rear end of the aircraft while the aircraft is in flight. The drone is provided with fins which provide directional control and aerodynamic stability during flight. Prior to the drones being deployed from the aircraft, the fins are typically folded in a stored position about the drone body in order to conserve storage space and to minimize handling and launching problems. The fins are deployed at the same time in which the drone is released from the aircraft. A spring actuated device deploys the fins in a quick manner so that the drone may immediately take advantage of the aerodynamic benefits of the fins. However, if the fins of the drone deploy too quickly, the fins may engage the rear portion of the aircraft thereby damaging the aircraft or the fins of the drone. The deployment of the fins must be slowed or dampened a sufficient degree to ensure that the fins do not engage the rear of the aircraft while also ensuring that the fins deploy sufficiently fast enough so that the drone may immediately benefit from the aerodynamic stability and directional control provided by the fins.
The aircraft utilizing the drones may deploy the drones at a wide variety of elevations. Such elevations create a wide array of temperatures for which the drones are utilized. Conventional shock absorbers and dampeners cannot provide consistent performance characteristics over such a wide array of temperatures because they typically utilize a fluid medium which expands and contracts under such temperatures. Due to the precision that is required in deploying the drones from an aircraft, any dampener or shock absorber developed to dampen the deployment of the fins of the drone must provide consistent performance characteristics regardless of the temperature. In addition, the area in which the shock absorbers and dampeners must operate on the drone is relatively small thereby requiring such a device to be compact and somewhat aerodynamic.
It would be desirable to provide a compact, inexpensive dampening apparatus that provides consistent and accurate performance characteristics over a wide array of temperatures.
The present invention provides a compact dampening apparatus that provides consistent performance characteristics over a wide array of temperatures. The invention provides a fluid filled housing having a first chamber, a second chamber, and a passageway therebetween. A first piston is slidably received within the first chamber of the housing for movement from a pre-actuated position to an actuated position. A second piston is slidably received within the second chamber of the housing for movement from the pre-actuated position to the actuated position. A spring is disposed within the second chamber for biasing the second piston toward the passageway and maintaining a constant level of fluid pressure within each chamber of the housing. An exhaust port communicates with the second chamber wherein the second piston is disposed between the passageway and the exhaust port in the pre-actuated position, and wherein the exhaust port is located between the passageway and the second piston when in the actuated position to allow fluid to escape through the exhaust port.
The first and the second chambers of the housing each have longitudinal axes that are substantially parallel to one another. The passageway connecting the first and second chambers has a longitudinal axis that is substantially perpendicular to the longitudinal axes of the first and second chambers. The passageway has a cross-sectional opening that is smaller than the smallest cross-sectional opening of the first and second chambers.
A positioning member is connected to the housing and the first piston for positioning and holding the first piston in the pre-actuated position. A positioning member releases the first piston under a predetermined load applied to the first piston allowing the first piston to be driven to the actuated position. The first piston is engageable with an actuating member to dampen the speed at which the actuating member actuates.